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CO2 capture using amine processes: International cooperation and exchange

Final Report Summary - CAPRICE (CO2 capture using amine processes: International cooperation and exchange)

The overall objective of CAPRICE was international cooperation and exchange in the area of CO2- capture using amine processes with the long-term aim to contribute to the implementation of these technologies on a large scale.

The overall objective was to be achieved through cooperation between a core team from the ongoing CASTOR Integrated Project and a Canadian consortium linked to the International Test Centre on CO2 Capture at the University of Regina in Canada. Both projects were recognised by the Carbon Sequestration Leadership Forum (CSLF). In addition to this, leading academic institutions from Russia, China and Brazil will join this research cooperation.

The detailed technical project objectives were as follows.

- Benchmarking and validation of amine process performance
A common data sheet with pilot plant layout and standardised input format was developed and accepted. Data from the NTNU/SINTEF pilot plant, DEG pilot plant, Stuttgart pilot plant, and ITC pilot plants are collected. These data comprise all pertinent information on size, packing material, capacity and equipment. In addition detailed data is collected from the runs performed in the various plants with 30 wt monoetanolamine (MEA) as absorbent.

The data have been validated based on a set of agreed criteria and a selected set of 16 runs for benchmarking has been established and stored in a database. Ford Foundation International Fellowships Program (IFP) and ITC have exchanged information on lab scale experiments and on corrosion monitoring carried out respectively on CASTOR and ITC pilot plants. Simulation runs in different available commercial program packages such as Aspen, Protreat, ProMax, have been performed and compared. Differences in the results were analysed and reasons for the differences discussed.
Also in-house program codes were tested and evaluated against the commercial codes. Guidelines for the recommended level of detail in such models are given.

- Membrane contactor performance validation
PTFE (UoR) and PP (Nederlandse Organisatie voor Toegepast Natuurwetenschappelijk Onderzoek or TNO) absorption membranes were manufactured. Absorption tests have been performed by UoR and TNO. Proof of principle has been established. TIPS has manufactured test pieces of high-temperature resistant desorption membranes. Desorption tests have been performed by TIPS and TNO. Proof of principle has been established.

Novel membrane materials able to operate at temperatures typical of stripper conditions (100 - 120 degrees Celsius) have been identified. These membranes have been screened for gas permeability (N2, O2, CO2) and water vapour permeability. These materials were built in membrane modules. After characterisation of the modules at regeneration conditions with MEA and other solvents, performance tests have been conducted (TNO). TIPS has manufactured test pieces of high-temperature resistant desorption membranes. Desorption tests have been performed by TIPS and TNO. Proof of principle has been established.

- Development of tools for integration into power plants
A model for simulation of major gas path plant such as flue gas desulfurisation (FGD) and draft plant was developed and utilised to optimise relative positions of these plant items. Process modelling of the CO2 capture plant was carried out by U of R and data fed into the EON UK overall power plant model to optimise positions for steam extraction and heat re-integration, as well as work out efficiency penalties incurred by the introduction of post combustion capture plant to a set of power plant cases. Simultaneous modelling of an integrated ammonia based capture plant and Chinese coal fired power plant was carried out by THU. Combination of existing tools can be used for integration of capture plants into power plants.

The options for linking together the major equipment items including FGD plant, FGD polisher (if applicable), amine scrubber, gas/gas heat exchanger (if applicable) flue gas fans, by-pass ducts and stack was assessed, including fan positions before and after the FGD plant, fan duty requirements and design types, gas by-pass requirements for FGD and amine scrubber, process plant control philosophy including start-up and shut down, implications of reheat requirements and reheater design, the need for a flue gas cooler in addition to FGD plant and the need for additional SO2-removal. Indicative costs, the potential advantages and disadvantages and reliability issues of each option were identified.%
LEON UK provided U of R with the design and flue gas conditions for one European coal fired and one Canadian lignite fired power plant case. For each case, the U of R used their MEA process model to determine the heat input and output conditions under an agreed set of operating conditions.

EON UK then input this data into their PROATES whole power plant process model to calculate the efficiency penalties arising from introducing the chosen CO2 capture plant to the specified base case power plants. PROATES was used to optimise the positions from which steam was drawn and low-grade heat/water re-introduced to the power plant steam/water cycle. Heat requirements and temperatures within the amine scrubber plant was obtained from the CO2 capture plant models operated by U of R, based on experimental data from their 1 tonne CO2/ day pilot plant.

THU carried out an equivalent study using their own ammonia scrubber process models and power plant efficiency models based upon a Chinese 300 MW power plant base case. Initially the plan also included modelling a gas fired power plant case. This case was however deemed of less immediate interest to the project parties, it was decided to omit this case from the work scope and focus on the coal fired cases.

The engineering consequences of drawing the required amount of heat/steam from the power plant steam cycle and of returning water and low grade heat back into the cycle was evaluated. This included the options available for modification of the steam turbine. By means of engineering assessment and PROATES modelling, the efficiency of the modified power plant when operating without the amine scrubber in service and without the concomitant loss of steam from the cycle was estimated. Implications on power plant systems like cooling water, process water and wastewater plant by the addition of post combustion capture plant were investigated. The implications of amine scrubber start-up and shut down on power plant control and electrical output response was also examined.

All public summaries of the deliverables can be found on the CAPRICE website, at online.